Meningioma of the scalp. Light and electron microscopic observations.

Meningiomas occurring in the skin are rare and may be difficult to recognize on frozen section. We found intraoperative cytologic smears helpful in identifying the characteristically bland nuclei, cellular whorls, and psammoma bodies that are typical of the light microscopy of meningiomas in the CNS. This case (a scalp lesion) was also examined ultrastructurally. Cutaneous meningiomas are histologically and ultrastructurally identical to their meningeal counterparts and must be approached with caution surgically.